As is well known, a check valve is used to permit the flow of fluid traveling in a flow line in one direction while stopping flow in the opposite direction. Commonly, the prior art check valves permit the direct passage of the flowing fluid over a sealing surface located on the valve body. Thus, the sealing surface becomes eroded by the fluid action and expensive procedures, such as removal of the valve from the flow line and machining the sealing surface to repair the valve or replacing the valve in the flow line, are necessary to insure the stoppage of fluid flow from the opposite direction.
Accordingly, it is an object of the present invention to provide a check valve which permits the flow of a fluid through a flow line in one direction while stopping fluid flow in the opposite direction.
Further, it is an object of the present invention to provide a check valve which requires less maintenance than the prior art check valves and is thereby more dependable and less expense for use in flow lines.
Further, it is an object of the present invention to provide a check valve which permits fluid flow in a flow line in one direction while stopping flow in the opposite direction and inhibits the erosive forces acting on the sealing surfaces.
In accordance with the invention, a check valve is used in a fluid flow line and includes a valve body having a first portion with an inlet end for directing the flow of fluid from the flow line through an inlet passageway, an outlet end for directing the flow of fluid received from the inlet passageway through an outlet passageway into the fluid flow line, and a flow channeling shoulder mounted at a junction between the inlet and outlet passageways for directing fluid flow upwardly from the inlet passageway through an opening into the outlet passageway, and a second portion with a tubular section defining a longitudinal passageway with outlet ports extending transversely therefrom, the tubular section being mounted in the opening of the first portion to receive the flowing fluid from the inlet passageway in one end of the longitudinal passageway for fluid flow up the tubular section and out the outlet ports into the outlet passageway. A flange extends outwardly from the tubular portion at a location below the outlet ports to define an upwardly facing sealing surface with the upwardly facing sealing surface being disposed sufficiently below the outlet ports to inhibit erosion thereof by flowing fluid. A plunger member is mounted within the body and includes a plug mounted on a lower portion of the plunger member for sliding within the longitudinal passageway of the second portion of the body and a tubular sleeve is mounted with the plunger member and circumscribes the tubular section. The sleeve has a shoulder which forms a downwardly facing sealing surface, the surface being engageable with the upwardly facing sealing surface on the flange. The sleeve is moved upwardly fluid pressure exerted on the plug against a force provided by a spring mounted with the plunger member for urging the downwardly facing sealing surface into engagement with the upwardly facing sealing surface which thereby prevents fluid communication between the inlet and outlet passageways by stopping fluid flow into the outlet ports when the pressure of the fluid within the inlet passageway is insufficient to overcome the force provided by the spring.